Thin films of both micro- and nano-particles are of technological interest. Such films can provide new and different properties to articles coated therewith, including chemical, optical and electronic properties, as well as various surface properties. Examples of articles that include coatings to provide desired properties include photonic crystals; lasers formed of two-dimensional assemblies of colloidal particles; films for altering surface properties such as conductivity on composite substrates for sensor applications; waveguides; coatings for modifying wetting properties; and surface enhanced raman spectroscopy (SERS) substrates.
Methods of forming micro- and nano-particle coatings are many and varied. Most of the methods however have limited practical applications because of small sample sizes, slow coating rates, difficulty in controlling the coating thickness, the need for complex equipment, or a combination of these problems. A recent advance in coating techniques includes a method of forming a monolayer of particles on a supporting fluid. This method solves some of the above mentioned problems but other problems remain.